Line rasterisation: Cover all pixels, regardless of line gradient?

Question

Basically, I want to use a line algo to determine which cells to check for collisions for my raycaster.

Bresenham isn\'t great for this as it uses a unified-thicknes

Answer 1

Without loss of generality, assume x2 >= x1, then

int x = floor(x1);
int y = floor(y1);
double slope = (x2 - x1) / (y2 - y1);
if (y2 >= y1) {
  while (y < y2) {
    int r = floor(slope * (y - y1) + x1);
    do {
      usepixel(x, y);
      ++x;
    } while (x < r);
    usepixel(x, y);
    ++y;
  }
}
else {
  while (y > y2) {
    int r = floor(slope * (y - y1) + x1);
    do {
      usepixel(x, y);
      ++x;
    } while (x < r);
    usepixel(x, y);
    --y;
  }
}

The floor calls can probably be written just as a cast-to-integer.